Responses of animals to many therapeutic and prophylactic drugs are mediated through receptors which reside on cell surfaces. One class of such receptors comprises the G-protein-coupled receptors, whose physiological effect is mediated by a three-subunit protein complex, called G-proteins, that binds to this type of receptor with the subsequent release of a subunit, thus setting in motion additional intracellular events. Receptors of this subclass include, among others, adrenergic receptors, neuropeptide receptors, the thrombin receptor and the C140 receptor which is the subject of the herein invention. This class of receptor is characterized by the presence of seven transmembrane regions which anchor the receptor within the cell surface.
It is the elusive goal of the designers of therapeutic substances to effect a desired response in a subject in the absence of side effects. Accordingly, pharmaceuticals designed to target a specific receptor, such as the thrombin receptor, should react with the thrombin receptor specifically and have no effect on related receptors. The C140 receptor of the present invention may be involved in controlling vascular pressure, and inadvertent stimulation or blocking of this receptor would have unpredictable and therefore undesirable results. It is therefore useful to determine in advance whether therapeutic reagents designed to target, for example, the thrombin receptor will or will not have the undesired side effect of reactivity with the C140 receptor. By providing the recombinant materials for the production of the C140 receptor in convenient assay systems, as well as agonist and antagonist reagents for use in this assay, the invention makes possible the prior determination of the presence or absence of the side effect of reactivity with the C140 receptor in candidate pharmaceuticals. This side effect will usually be undesired as it is believed that the C140 receptor responds to enzymes such as serine proteases associated with trauma and immune disturbances.